There is a growing usefulness in determining the presence, permanence and location of passengers and drivers, inside and outside a vehicle. Current occupant detection and location systems utilize cameras, seat sensors and key-fob or mobile device detection. Each of these systems has some drawbacks, however.
Camera systems can be expensive due to requisite computational power and optics requirements, so that a vision system camera can distinguish one face from another. Additionally, users being recognized must be in view of the camera and cannot have any obstruction (scarf, coat collar, hat etc) blocking a recognizable portion of their face. Further, ambient conditions such as glare from excessive sunlight or a dark environment can cause difficulty in recognizing faces.
Seat sensors can detect weight in a seat, but cannot necessarily distinguish between a load and an occupant. Further, since multiple people may have similar weights, the sensor may have difficulty assigning an identity to a detected occupant.
Fob detection works for the driver (and any other occupant carrying a fob. A problem with this is that another party (spouse, child) could be carrying the fob, and the system may have no way of discerning which party is carrying the fob. Similarly, mobile phone detection may work reasonably, but shared phones and phones left lying in vehicles can cause some confusion, either because a wrong party is identified (the wrong party being in possession of another's phone) or because a phone left in the vehicle causes an identification of a non-present party.
If a vehicle can accurately identify and locate the individual occupants, the vehicle can leverage a variety of useful related services. Content can be directed to those occupants (e.g., favorite media, children's media for children, etc.), services can be offered to those occupants, and even medical information on a per-occupant basis can be known.